Light emitting diodes (LEDs) are a popular lighting solution for many applications. LEDs have a number of benefits including longer life and lower energy usage than traditional lighting solutions such as incandescent lights. In general, one or more LEDs are attached to a circuit board. Typical circuit boards include electrically conductive traces sandwiched between two electrically insulating surfaces. The electrically insulating surfaces may be made from a glass-reinforced epoxy such as FR4 or an insulated metal substrate (IMS). Another type of circuit board used for LED arrays is a flexible circuit board. Here, the traces are sandwiched between flexible insulating surfaces such as polyimide.
One technical challenge associated with LED lighting arrays is the dissipation of heat generated by the LED. Unlike other light sources, visible-spectrum LEDs only dissipate a small portion of their heat by radiation. Heat degrades LED performance and reliability. For example, a higher junction temperature results in lower light output from the LED and shorter lifetime. There is thus a need for a circuit board with good thermal management to increase lumens output without overheating, resulting in higher performance lighting products.